This section provides background information related to the present disclosure which is not necessarily prior art.
Short Message Service (SMS) provides a method for transferring a message of certain size between terminals or between a terminal and a network, with a successful application in a cellular network of a CS domain. A network entity called as short message center is introduced in the implementation of the SMS, and thus short message forwarding, storing and deferred delivery and other value added services may be implemented. The GSM/UMTS Public Land Mobile Network (PLMN) is required to support a short message forwarding function between a short message center and terminals.
An IP multimedia subsystem (IMS) is a subsystem added in the 3GPP R5 on the basis of the existing PS domain. The IMS employs the PS domain as a bearer channel for the transmission of its upper level control signaling and media data, adopts a Session Initiation Protocol (SIP) as an IMS service control protocol, and provides abundant multimedia services for subscribers by separating the service control from the bearer control, and by utilizing the characteristics of the SIP, i.e., simple, extensible and convenient for a media combination. A network integrated solution of IMS allows operators to provide fixed users and mobile users with the same service based on a unified core network. For a network structure with the core networks of fixed network and mobile network coexisting, not only the complexity of the network structure may be reduced but also the cost of operation and maintenance may also be cut down.
For the network structure for implementing SMS, there is weak control on a short message MT, and there are defects in filtering the junk short message, and implementing lawful intercept and some value-added short message services. Therefore, a network structure of MT short message center is introduced in the 3GPP specification. In view of the successful application of the SMS in the existing cellular system, it is taken into account to expand the SMS to be employed in non-cellular IP connection networks in the 3GPP specification. It is defined in the TISPAN that an AS in the IMS stores and forwards a short message and handles a supplementary service of the short message. And at the 3GPP conference, how to distinguish a short message procedure in the IMS from an inter-domain short message procedure began to be taken into consideration. Therefore, one of the problems to be solved by the 3GPP is to consider how to integrate the network structure of the MT short message center and the network structure for short message interworking and to consider that an AS in the IMS stores and forwards a short message and handles a supplementary service of the short message so as to form a valuable product.
Prior art I: The network structure for short message interworking as defined by the 3GPP is shown in FIG. 1, and the function of each network entity is described as follows.
SMSC: Short Message Service Center, is configured to relay, store and forward a short message between a base station and a Short Message Entity (SME); a protocol between Mobile Equipment (ME) and SMSC can transmit the short message from or to ME. The protocol is Short Message Transmission Protocol (SMTP).
SMCIWMSC/GMSC: SMS-Gateway MSC, i.e., SMS gateway, is configured to receive a short message sent by the SMSC, and query the HLR for the routing information, and transmitting the short message to a switching center of a base station where a receiver resides.
IP-SM-GW: IP Short Message Gateway, is configure to provide a interworking function between the UE and GSM/UMTS network to transmit a short message. An AS in the IMS may serve as an IP-SM-GW entity.
HLR/HSS: Home Location Register/Home Subscriber Server, is configured to provide the SMS service with a routing function. In the Mobile-Terminated (MT) procedure, the GMSC sends a routing request message to the HLR/HSS; if the UE previously registered the address of the IP-SM-GW, the E.164 address of the IP-SM-GW contained in a routing response message is returned to the GMSC.
In view of the above network structure for short message interworking as already defined by the 3GPP, the procedure for registering an SMS as shown in FIG. 2 includes the following:
The UE initiates a normal registration/re-registration procedure.
The S-CSCF checks a triggering rule, finds out the address of the IP-SM-GW, and triggers a third party registration procedure.
The IP-SM-GW stores the address of the S-CSCF.
The IP-SM-GW initiates a registration procedure to the HSS/HLR.
The HSS/HLR stores the E.164 address information of the IP-SM-GW, and returns a response.
The IP-SM-GW returns a response to the S-CSCF.
The S-CSCF returns a response to the UE.
In view of the above network structure for short message interworking as already defined by the 3GPP, its short message MT procedure (Mobile-Terminated short message procedure) as shown in FIG. 3 includes the following:
The UE registers at the S-CSCF via an IMS registration procedure with the above short message registration procedure performed.
The SM-SC forwards an SMS message to the SMS-GMSC.
The SMS-GMSC sends a routing request to the HLR/HSS. The routing request contains an indicator indicating that the SMS-GMSC supports IP message routing.
The HSS/HLR returns a registered E.164 address of the IP-Message-GW to the UE;
The SMS-GMSC sends the SMS message to the IP-Message-GW. The SMS message contains the MSISDN of the UE.
Convert the MSISDN into a TelUrl, and find the corresponding S-CSCF address according to the TelUrl.
The IP-Message-GW sends the SMS message to the S-CSCF.
The S-CSCF forwards the SIP MESSAGE to the UE.
The UE returns a 200 OK response to the S-CSCF.
The S-CSCF sends a 200 OK to the IP-Message-GW.
The UE sends a delivery report to the S-CSCF via the SIP MESSAGE.
The S-CSCF forwards the SIP MESSAGE to the IP-Message-GW according to a filtering rule.
The IP-Message-GW sends the delivery report to the SMS-GMSC.
The SMS-GMSC sends the delivery report to the HLR/HSS.
The SMS-GMSC sends the delivery report to the SM-SC.
The IP-Message-GW gives the S-CSCF an acknowledge message via a 200 OK.
The S-CSCF gives the UE an acknowledge message via a 200 OK.
In prior art I, only the state of a user in the IMS and the relation between the user and an S-CSCF are registered on the IP-SM-GW without the case that the user registers on both CS domain and IMS taken into consideration. Therefore, when a user registers on both CS domain and IMS, it is impossible to determine to route a short message to whether the CS domain or the IMS according to conditions such as the state, capability and preference of the user. And due to the lack of a mechanism for recording a routing control method in the case of multiple IP connections in the IMS, an intelligent control cannot be exerted on the further routing of a short message after the short message reaches the IMS. Due to the lack of the short message center at the MT, an enhanced control can not be exerted on the short message at the MT.
Prior art II: a network structure with an MT short message center introduced is shown in FIG. 4.
For the procedure for registering an SMS in the IMS, refer to prior art I.
The procedure for sending a short message includes the following:
I. A user in the CS domain sends a short message to a user having a single subscription in the IMS:
An UE in the CS domain sends a short message via an MSC.
The MSC parses a short message center address in the short message, and sends the short message to an MO-SMSC via an SMS-IWMSC upon making a route analysis.
The MO-SMSC queries an HSS/HLR for an MT-SMSC, and sends the short message to the MT-SMSC.
The MT-SMSC sends the short message to an SMS-GMSC.
The SMS-GMSC queries the HSS/HLR for the routing information of the called user.
The HSS/HLR returns the address of the IP-SM-GW.
The SMS-GMSC sends the short message to the IP-SM-GW.
The IP-SM-GW sends the short message to the S-CSCF recorded when the third party registers.
The S-CSCF routes the short message to the UE.
II. A user in the IMS sends a short message to a user having a single subscription in the CS domain:
A UE in the IMS sends the short message to the IP-SM-GW via the S-CSCF.
The IP-SM-GW parses the address a short message center in the short message, and sends the short message to the MO-SMSC via the SMS-IWMSC upon making a route analysis.
The MO-SMSC queries the HSS/HLR for the MT-SMSC, and sends the short message to the MT-SMSC.
The MT-SMSC sends the short message to the SMS-GMSC.
The SMS-GMSC queries the HSS/HLR for the routing information of the called user.
The HSS/HLR returns the number of the MSC where the called user currently resides.
The SMS-GMSC sends the short message to the MSC where the called resides.
The MSC sends the short message to the called user by paging.
III. A user in the CS domain sends a short message to a user having a single subscription in the CS domain:
A UE in the CS domain sends a short message via an MSC.
The MSC parses the address of a short message center in the short message, and sends the address the short message center to an MO-SMSC via an SMS-IWMSC upon making a route analysis.
The MO-SMSC queries an HSS/HLR for an MT-SMSC, and sends the short message to the MT-SMSC.
The MT-SMSC sends the short message to an SMS-GMSC.
The SMS-GMSC queries the HSS/HLR for the routing information of the called user.
The HSS/HLR returns the number of the MSC where the called user currently resides.
The SMS-GMSC sends the short message to the MSC.
The MSC sends the short message to the called user by paging.
In prior art II, although the control on the MT is enhanced by introducing the short message center at the MT, that the user subscribes to both CS domain and IMS is still not taken into consideration. Therefore, if the user subscribes to both CS domain and IMS, it is impossible to determine to route the short message to whether the CS domain or the IMS. Due to the lack of a high level decision mechanism, the routing capability of the short message is weak, and the intelligent routing control cannot be exerted according to the user's preference, operator's strategy, user's registration state, etc.
Prior art III: A schematic drawing of network architecture illustrating a short message routing method in the IMS as defined by the TISPAN is shown in FIG. 5.
In view of a network architecture based on a short message routing method in the IMS as defined by the TISPAN, a short message routing procedure includes the following:
The UE in the IMS sends a short message to the S-CSCF.
The S-CSCF, according to a filtering rule, triggers the AS-SMS to perform the service control of a calling user and a necessary redirection (when the address of a called user is encapsulated in the short message) without storing the short message, and the AS-SMS, in turn, sends the short message to the S-CSCF. If only the requirement in the TISPAN is taken into consideration, this step is optional.
The S-CSCF parses the DNS, queries the address of the I-CSCF, and sends the short message to the I-CSCF.
The I-CSCF queries the UPSF (i.e., HSS/HLR) to obtain the address of the S-CSCF where the called user resides, and forwards the short message to the S-CSCF where the called user resides.
The S-CSCF where the called user resides sends the short message to the AS at the MT according to a triggering rule.
The AS at the MT returns the short message to the S-CSCF at the MT upon performing a supplementary service handling.
The S-CSCF at the MT routes the short message to the UE.
In the TISPAN, only the implementation procedure of the short message in the IMS is taken into consideration, but the short message interworking with the CS domain and the inter-domain route if the user subscribes to both CS domain and IMS are not taken into consideration. Also lacked is the capability of enhancing control on the MT.
The inventor found in designing the disclosure that the prior art cannot satisfy the demand for implementing the enhanced routing control so as to deliver the short message when multiple paths exist.